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I am able to get my hands on an M130 which originally came out of a Mercedes 280. All the required modifications for it to fit in a 404 have been made.

But...

The engine was left out over the winter and now has a small crack in the block
I am waiting to receive pictures of where the crack is however I just wondered if there is a weak spot were the block normally cracks?

Is the crack likely to be repairable?

If not is it still worth buying, just for parts that have been converted to allow it to be fitted to a mog

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Wait... I looked at it again, and it looks like it's cracked where the head is attached to the block, so I don't know if you could pin it. I have heard of people welding blocks, but it's not very easy.

http://www.locknstitch.com/CastIronWelding.htm - "The most important thing for you to understand is that electric welding on cast iron is actually the very worst decision you could make to attempt to repair your cracked cast iron part. If you want to make a complete mess of your part, go ahead and arc weld it with nickel rod. Cast iron cannot stretch and withstand the contraction and hardening caused by cast welding with preheating below 1200 deg. F. The brand of welding rod does not make a very big difference. It's the heat that causes the changes to the cast iron itself. Sure the nickel weld is machineable but the cast iron will become as hard as a drill bit or tap and therefore will prevent the proper machining that is often required. 50% of the casting repairs we see have been arc welded on with disastrous results often costing the owner at least twice as much to repair properly. Cast iron welding should not be attempted even by experienced welders without years of high temperature oven welding training. Cast iron requires preheat of at least 900 deg. F. for brazing and 1300 deg. F. for fusion welding. "

I've attached a drawing a I made of how "pinning" works, or at least how I understand it. I think some people call it locking or stitching too. To me, none of the 3 really describe what is done, but pinning comes closest.

You drill holes, tap the holes, and then turn in pins. In this case the first step used 10 "pins".

After you have the pins turned in, I think you then grind them flat with the block and then in between each pin you drill more holes and insert more pins.

There's no welding involved. I think the pins are made of iron too, that way you don't have to worry about different expansion rates.

If there's a crack on top of the block or in one of the cylinders, obviously this technique wouldn't work as well.

Attachments

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Doesn’t sound too positive at the moment. It’s a bit difficult to work out the extent of the damage with the pictures I’ve been given, really needs the head to be taken off.

I still think it might be worth buying since all the required modifications for it to fit in a 404 have been made.

Even if this block works out to be scrap it will still give me some spares and save me some time. The modifications to the Flywheel, Clutch and oil pan for it to fit a 404 have already been made so I could simply swap them over to another M130.

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The modifications made are not that complex so keep it in mind when negotiating the price.

Oil Pan Grinding - about an hour with test fits

Flywheel Balancing - This could be where you make the deal. Find out if they used a "Thick Flange" flywheel for this modification or just the regular thin flange flywheel. If it is a thick flange it has some value as those flywheels have become very rare. (we've been out for upwards of 2 years.) We usually sub this to our machine shop and it runs about $100-150.

If the block did not have anti-freeze and just water and froze...are you sure this is the only damage?

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I'd go with the above. If the crack was down the side of the block then it could be stiched (not cheap, but ugly and effective). If it's on the top face, that block is scrap.

How easy it is it get an m130 in the UK? Buy an classic merc 280 and pull the engine out of it. You'll be fighting with the classic merc restoration guys though who'll be wanting to put it in their 280 cars though.

With regards to buying it and saving time getting a block, I'm not sure you'd save any time at all. Have you ever swapped a block on a motor? Every nut and bolt pretty much has to be removed. You'd be better looking for a complete one and swapping the flywheel and sump (about a dozen bolts)

Did you not sell your mog Tom? I thought you were having problems driving it due to the weight restriction on your licence?

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Depending on how bad it's cracked and where, it can be welded, but the block has to be put into a furnace and heated to about 1200° before being welded. Most of the time they're only welded if they're rare blocks, like a block for a 1933 Duesenberg where you can't even find blocks anymore. Probably cost you an arm and a leg to even try to find a place that will do it.

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If the block is not cracked through to the cylinder but just to the cooling chamber it can be welded without bringing the entire block up to temperature. The rate of cooling is much more important than the rate of heating. I have welded several blocks including a power stroke diesel recently without preheating the entire block. Grind it out well, preheat the area with a torch, weld it, throw a shovel of live coals over it (charcoal briquettes work well) and cover it with tinfoil and a steel box. Find an experienced fab shop in your area and ask them about it before you by it.

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If the block is not cracked through to the cylinder but just to the cooling chamber it can be welded without bringing the entire block up to temperature. The rate of cooling is much more important than the rate of heating. I have welded several blocks including a power stroke diesel recently without preheating the entire block. Grind it out well, preheat the area with a torch, weld it, throw a shovel of live coals over it (charcoal briquettes work well) and cover it with tinfoil and a steel box. Find an experienced fab shop in your area and ask them about it before you by it.

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You can’t put enough heat in the block by welding it to warp it unless you are trying to. That’s a huge mass of steel there. The biggest concern is it cracking along the heat line parallel to the weld. By allowing it to cool gradually over several hours the stress along that line is reduced. I have welded a lot of cast over the years and have had good results doing it. Small parts like exhaust manifolds I weld right in a bed of hot coals then let them cool over night.

I’d buy that motor in a heartbeat if the price was right. Where is it located?

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You can’t put enough heat in the block by welding it to warp it unless you are trying to. That’s a huge mass of steel there. The biggest concern is it cracking along the heat line parallel to the weld. By allowing it to cool gradually over several hours the stress along that line is reduced. I have welded a lot of cast over the years and have had good results doing it. Small parts like exhaust manifolds I weld right in a bed of hot coals then let them cool over night.

I’d buy that motor in a heartbeat if the price was right. Where is it located?

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You can’t put enough heat in the block by welding it to warp it unless you are trying to. That’s a huge mass of steel there. The biggest concern is it cracking along the heat line parallel to the weld. By allowing it to cool gradually over several hours the stress along that line is reduced. I have welded a lot of cast over the years and have had good results doing it. Small parts like exhaust manifolds I weld right in a bed of hot coals then let them cool over night.

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That’s incredible to me. We would make that repair for under $150. What’s the going shop rate in the UK?

It does look like the crack continues to the top planed surface. If it were mine I would weld it and hand scrap it back using bluing and a machinist straight edge. It’s time consuming but wouldn’t cost me anything dollar wise.

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To get it planed would cost about the same as I paid for an m180 HC recently. That's not including time to strip, new gaskets or owt else. I'd be surprised to see change from 500 gbp to get that repaired and the engine upland running again.

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If your patient, you can get an M130 here in albuquerque for less than $200. Would likely just need freshening up. We have tons of old merc cars here in New mexico. Very sad seeing beautiful old pontoon's being smashed at the local pic and pull.

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